Treatment Efficiency Of Neer 3-and 4-part Proximal Humeral Fractures With Nano-hydroxyapatite/collagen And Allograft

Objective:The purpose of this study was to evaluate the reliability of nano-hydroxyapatite/collagen for structural bone grafting in treating Neer 3-and 4-part valgus proximal humeral fractures and compare their outcomes with those when allograft bone is used.Methods:We retrospectively analyzed the patients in our medical group who suffered from Neer 3-or 4-part valgus proximal humeral fractures and underwent open reduction and internal fixation with bone grafting,using nano-hydroxyapatite/collagen or allograft bone from January 1^st2015 to December 31^st2017.There were 14 and 13 patients who received the bone grafting respectively.Basic information of the patients was gathered as well as that relevant to the operations.Statistics were recorded during the terminal follow-up until one and a half years after operation,including neck-strut angle and its change,VAS scores,Constant-Murley scores,relative strength of deltoid and supraspinatus,and postoperative complications.Results:There were 13 and 12 patients who received entire follow-up in the nano-hydroxyapatite/collagen group and allograft group respectively.The ages of patients of the two groups were 63.46±11.27 and 60.67±9.74.It took2.12±1.39 and 2.83±1.27 days for the patients before undergoing the operation.The numbers of screws used in the operation were 10.31±0.63 and10.25±0.62.The volumes of bone graft used were 4.39±0.46cm3and4.71±0.69 cm3.The operations took 119.62±44.42 and 98.75±21.65 minutes respectively.The postoperative neck-strut angles were 131.46±4.46 and130.85±3.56 degrees.And the hospitalizations lasted for 6.15±1.99 days and6.92±1.68 days.There were no significant differences in the above data between the groups（P>0.05）.At the terminal follow-up,the neck-strut angles were 131.61±3.85 and 130.50±4.41 degrees respectively while the changes of which were 0.15±5.00 and-0.35±2.38 degrees with no significant differences（P>0.05）.VAS scores were 2.62±0.87 and 2.17±0.84.The nano-hydroxyapatite/collagen group reached a lower level in Constant-Murley scores,relative strength of deltoid and supraspinatus,but with no significant differences compared with the allograft group（P>0.05）.During the entire follow-up,no obvious complication was observed,including wound drainage,abnormal wound healing,infection and avascular necrosis of the humeral head.Conclusion:Nano-hydroxyapatite/collagen was associated with good outcomes in structural support and stability augmentation in treating Neer 3-or 4-part valgus proximal humeral fractures.And this material is relatively cheap,easy to be prepared,and with good biocompatibility.In addition,there was no risk of disease transmission from the donor compared with allograft bone.Furthermore,nano-hydroxyapatite/collagen can lead to good clinical outcomes equal to allograft bone,which brings promising potential for clinical applications.